mesh_generator_thread.h

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/*
Minetest
Copyright (C) 2013, 2017 celeron55, Perttu Ahola <celeron55@gmail.com>
 
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.
 
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
 
#pragma once
 
#include <ctime>
#include <mutex>
#include "mapblock_mesh.h"
#include "threading/mutex_auto_lock.h"
#include "util/thread.h"
 
struct CachedMapBlockData
{
    v3s16 p = v3s16(-1337, -1337, -1337);
    MapNode *data = nullptr; // A copy of the MapBlock's data member
    int refcount_from_queue = 0;
    std::time_t last_used_timestamp = std::time(0);
 
    CachedMapBlockData() = default;
    ~CachedMapBlockData();
};
 
struct QueuedMeshUpdate
{
    v3s16 p = v3s16(-1337, -1337, -1337);
    bool ack_block_to_server = false;
    int crack_level = -1;
    v3s16 crack_pos;
    MeshMakeData *data = nullptr; // This is generated in MeshUpdateQueue::pop()
 
    QueuedMeshUpdate() = default;
    ~QueuedMeshUpdate();
};
 
/*
    A thread-safe queue of mesh update tasks and a cache of MapBlock data
*/
class MeshUpdateQueue
{
    enum UpdateMode
    {
        FORCE_UPDATE,
        SKIP_UPDATE_IF_ALREADY_CACHED,
    };
 
public:
    MeshUpdateQueue(Client *client);
 
    ~MeshUpdateQueue();
 
    // Caches the block at p and its neighbors (if needed) and queues a mesh
    // update for the block at p
    void addBlock(Map *map, v3s16 p, bool ack_block_to_server, bool urgent);
 
    // Returned pointer must be deleted
    // Returns NULL if queue is empty
    QueuedMeshUpdate *pop();
 
    u32 size()
    {
        MutexAutoLock lock(m_mutex);
        return m_queue.size();
    }
 
private:
    Client *m_client;
    std::vector<QueuedMeshUpdate *> m_queue;
    std::set<v3s16> m_urgents;
    std::map<v3s16, CachedMapBlockData *> m_cache;
    std::mutex m_mutex;
 
    // TODO: Add callback to update these when g_settings changes
    bool m_cache_enable_shaders;
    bool m_cache_smooth_lighting;
    int m_meshgen_block_cache_size;
 
    CachedMapBlockData *cacheBlock(Map *map, v3s16 p, UpdateMode mode,
            size_t *cache_hit_counter = NULL);
    CachedMapBlockData *getCachedBlock(const v3s16 &p);
    void fillDataFromMapBlockCache(QueuedMeshUpdate *q);
    void cleanupCache();
};
 
struct MeshUpdateResult
{
    v3s16 p = v3s16(-1338, -1338, -1338);
    MapBlockMesh *mesh = nullptr;
    bool ack_block_to_server = false;
 
    MeshUpdateResult() = default;
};
 
class MeshUpdateThread : public UpdateThread
{
public:
    MeshUpdateThread(Client *client);
 
    // Caches the block at p and its neighbors (if needed) and queues a mesh
    // update for the block at p
    void updateBlock(Map *map, v3s16 p, bool ack_block_to_server, bool urgent);
 
    v3s16 m_camera_offset;
    MutexedQueue<MeshUpdateResult> m_queue_out;
 
private:
    MeshUpdateQueue m_queue_in;
 
    // TODO: Add callback to update these when g_settings changes
    int m_generation_interval;
 
protected:
    virtual void doUpdate();
};